I guess the next logical question is, why can't the makers of HIFI players make these palyers to have such frequency response like cheap FUZE, while retaining the other attributes for HI FIDELITY sound? Do they consider or is it an essential ingredient of the hifidelity sound to have skewed FR curve?
Fang already explained why he ditched the flat FR on the HM801 in favor for a slow roll off Butterworth filter almost 2~3 years ago (edit: I am more forgetful than I thought :p). I could only assume the R&D team over at HifiMan must have felt that the Butterworth filter sounds better to what other flat sounding filter they have tested / experimented. It is not a matter of what can or can't be done, but a choice they make consciously to achieve a sound that they are looking for. Whether the user can accept that conclusion or not, is of course up to the individual.
Edited by ClieOS - 7/20/11 at 6:44am